73-74 & 75 Air Cleaner differences
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Joined: Jul 2009
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73-74 & 75 Air Cleaner differences
From all the catalogs I've seen, the 73-74 dual snorkel air cleaner is different than the 75 dual snorkel air cleaner. It looks like the base is a different number, at the very least. What are the differences? I have an L82 73 Coupe that's missing the whole shebang! Thanks!
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Joined: Oct 2000
Posts: 12,683
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From: Shamong, NJ
The 75 air cleaner needs additional clearance at the back of it, to clear the larger HEI distributor and it's shielding. The 73-74 base and the ring for the seal, are different from the 75 air cleaner's pieces. The valve cover to air cleaner breather tube is different also. The 73-74 share the same tube, while the 75 uses the same tube as 76-81s. The lid and air cleaner to hood seal, are shared by all 73-75 air cleaners.
It's pretty difficult to tell the differences between the 73-74 base, and a 75 base, without having them side by side. I think the 75 base sits futher forward on the carb, than a 73-74 and the 75 ring, sits further back on the base, to correctly mate to the hood. The 73-74 ring can easily be identified by the 3 notches in it, the 75 ring has 4 notches.
Original bases that still have the AC "Keep your GM car all GM" label on it, can be identified by the code on the label. The 73-74 bases will either have a "DO" or "DB" code, 75 bases will have an "EJ" code.
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Joined: Jan 2007
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From: Danville Illinois
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My 75 air cleaner has the back of it con-caved in for the clearance of the HEI. As Gbvette62 says its hard to tell the difference without comparing them side by side.
Melting Slicks
Joined: Dec 2002
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From: Belmont Michigan
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Melting Slicks
Joined: Apr 2001
Posts: 3,399
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From: Olmsted Falls, Ohio
The 75 is not offset and it looks like the redesign from 74 was someone using a hammer on the distributor side of the base. Maybe they had to use up all the 74 stock laying around. Looks like a rough fix to me. I do know that base is not offset. A friend of mine found a used 74 and gave it the hammer treatment - Worked just fine. After all if the base was offset then the cowl induction ring to the hood would not be centered.
